Frame-shear Wall Research Articles

極限解析マクロモデルによる単独耐震壁の最大強度の解析精度

This paper describes analysis accuracy of maximum strength of isolated framed shear walls by limit analysis macro model. This model is established from analysis output by elasto-plasticity analysis macro model. This model is considered based on the lower bound theorem of the limit-analysis theory. This model can apply shear strength of frames. This model guesses maximum strength of experiments with sufficient accuracy, even when shear strength of frames is not applied. Furthermore, if it is applied, accuracy became better. It is shown that these results are effective for evaluation of maximum strength of isolated framed shear walls by this model.

Seismic Design and Analysis of Tall Shear Wall-Frame Structure Using Viscous Damping Wall

The design and analysis procedures of a viscous damping wall for a tall shear wall-frame structure in a high seismic region are briefly introduced. Design method and theoretical basis of viscous damping wall are described, and then the layout scheme is put forward. Under frequent and rare earthquake action, the analysis results of damping structure show that the responses can be reduced perfectly. The maximum story drift angle of viscous damping structure can satisfy the limitations of the seismic code and the additional damping ratio is increased to 3%, all of them can satisfy the target of damping performance.

Earthquake Response and Design of Energy Dissipation for a 22 Story Apartment Building

Vibration control of a 22 story RC frame-shear wall apartment building with large aspect ratio was studied in this paper. Three vibration control plan with mild steel dampers, viscous dampers and viscoelastic dampers were proposed to control structural dynamic responses under earthquake. The dynamic responses of the structure with the proposed control schemes under earthquake excitations were investigated and their vibration control effects were compared. The numerical analysis results show that structural dynamic responses under earthquake excitations can be decreased effectively using the proposed plan. The earthquake response with viscous dampers was smaller than that with mild steel dampers and viscoelastic dampers. The shear force, drift and the acceleration of the structure with viscous dampers were 20%-40% less than the structure without any dampers for the slender structure.

축력과 반복수평력을 받는 격자강판 내진보강벽의 구조거동에 관한 실험적 연구

근래에 지어진 건축물의 경우 지진에 대한 안전성을 확보하고 있지만 1983년 개정이전의 건축물은 내진설계가 미반영 되어 있어 지진에 대해 매우 취약하다. 본 연구에서는 내진성능이 부족한 기존 건축물의 지진 발생 시의 안전성 확보를 위한 내진보강 방안으로 격자강판 내진보강벽을 제안한다. 축력과 반복수평력을 받는 성능실험을 수행하였으며, 실험체는 벤치마크 용도로 순수 철근콘크리트 프레임(BM-RC)과 프레임 내부에 격자강판 내진보강벽(SW-RC)을 설치한 2개의 실험체를 제작하여 실험을 수행하였고, 축력과 횡하중 가력을 위하여 500kN용량의 엑츄에이터 2대와 2,000kN용량의 엑츄에이터 1대를 사용하였다. 실험결과를 통해 벤치마크 실험체와 비교하여 강도, 강성, 연성 및 에너지소산능력을 평가하였다. The recently constructed buildings are ensuring seismic safety with enhanced design criteria. But, the buildings unapplied enhanced design criteria are very weak. In this study, steel grid shear wall is proposed as a solution of seismic retrofit to ensure safety of the existing buildings for the earthquake. And the structural performance experiments were carried out under axial force and cyclic lateral loads. The two specimens were made of a reference RC frame and steel grid shear wall in-filled RC frame. The test setup configured with two dynamic actuators, for the axial force with a 500kN capacity actuator and for the cyclic lateral load applied with the 2,000kN actuator. Compared with control specimen, the strength, stiffness, ductility, energy dissipation capacity of the seismic retrofit structures is evaluated.

Effects of Openings in Shear Wall on Seismic Response of Structures

of reinforced concrete walls with different sizes of opening and reinforcing patterns around the opening. The test results indicated that the shear strength contributed by diagonal reinforcement around opening reached 40% of its yield strength, while the shear strength contributed by rectangular arrangement reached 20% of its yield strength. It was also concluded that shear capacity of section is not only affected by width of opening but also affected by depth of opening as well. Kim and Lee, 2003[3] proposed a method for the analysis of shear wall with openings using super elements to model the shear wall. Qaqish and Daqqaq, 2000[5] studied on effect of small openings on behavior of shear walls and the effect of opening size on behavior of coupled shear walls. Yanez, Park and Paulay, 1992[6] studied on seismic behavior of reinforced concrete walls with square openings of different size and arrangement under reversed cyclic loading. It was concluded that the stiffness of walls is dependent on the size of the openings not on their horizontal locations. It was suggested that the stiffness of walls without openings can be used for the stiffness of the walls with openings smaller than 10% of the wall area. In this study linear static analysis is performed on 6 story frame shear wall building keeping opening in shear wall (shell element is used to represent shear wall) with finite element software, ETABS[7] under earthquake loads in equivalent static method. The objective of this study is to know the effects of openings sizes and configurations in shear wall on stiffness as well as on seismic responses and explore the behavior of structural system so that a suitable configuration of openings in shear walls can be obtained.

Comparison and Research on the Cantilevered Steel Structure Roof of Weinan Hongji Building, Shanxi Province

The substructure of Weinan Hongji building in Shanxi Province is frame shear wall structure, supporting a cantilevered steel roof in the shape of an “official hat”. Two different design proposals were compared between pipe truss structure and steel frame. Space truss system was adopted in the middle large span part. Spatial analysis of the overall model was carried out using Midas730 software and 51types of load combinations were considered. The period, mode, strength and stiffness are compared and the result shows that the option 1 outperforms option 2.

Three-Spring Model for Spatial Walls

Shear wall structures, frame-shear wall structures and frame-tube wall structures are usually used in tall buildings, especially in China seismic regions. How to simulate the mechanical behaviors of these walls is the key to elastic-plastic analysis for tall buildings. Based on two-spring model, a nonlinear model for spatial walls is proposed. In this model, the axial, shear and flexural elastic-plastic deformation of the walls can be considered, the deformation compatibility between the wall and beam elements is also considered. The model was used to analysis the elastic-plastic behavior of spatial walls. Calculation example for verifying the model indicates that the result obtained by this method has the characteristics of fewer degrees of freedom and high accuracy. Therefore the nonlinear model for spatial walls provides a practical and efficient analysis method for tall buildings with complex type.

Seismic performance of reinforced concrete shear wall frames considering soil-foundation-structure interaction

SUMMARY A practical application of ‘beam on nonlinear Winkler foundation’ approach has been utilized in this paper for a case study on seismic performance of concrete shear wall frames to assess the soil–foundation–structure interaction effects. A set of 3-, 6-, 10- and 15-story concrete shear wall frames located on hypothetically soft, medium and hard soils were designed and modeled using the OpenSees platform. The numerical model of each frame was constructed employing the distributed and lumped plasticity elements as well as the flexure–shear interaction displacement-based beam–column elements incorporating the soil–footing interface. Pushover analysis was performed, and the results were studied through two code-based viewpoints: (a) force-based design and (b) performance-based design. A comparison was made afterwards between the frame behaviors in the fixed-/flexible-base conditions. The results indicate some degree of inaccuracy in the fixed-base assumption, which is regularly applied in analysis and design practice. The study emphasizes on how the fixed-base assumption overestimates the design of the wall element and underestimates the design of the connected moment frame. Copyright © 2012 John Wiley & Sons, Ltd.

Pushover Analysis of Eccentric High-Rise Single-Tower Building’s Frame-Shear Wall Structure

High-rise building with podium is a common seen architecture style in China. Nowadays more designers inclined not to separate the main and podium, but this would lead to the eccentric between the center of mass of the tower and base, which may exceed the code requirement when the ratio of offsetting is larger than 20% and cause complicated seismic response. This paper takes an eccentric high-rise frame-shear wall structure of single tower as example, analyze the inelastic performance of this structure under rare earthquake by Pushover method, and point out the weak parts of the position by the distribution and development of plastic hinges.Draw the structure inelastic response indicators in the rare case of earthquakes, and point out the weak parts of the structure of the distribution and development of plastic hinge (region), put forward reasonable proposals for optimizing the structure design.

Tilt Response of Multi-Storey Building of Different Types due to Progressive Collapse of the Adjacent Underground Structure under Internal Blast Loading

This paper numerically investigates the tilt response of multi-storey buildings due to progressive collapse of the adjacent underground structure under internal blast loading. The software LS-DYNA is utilized to establish a three-dimensional coupled model composed of the underground structure, the soil around and the adjacent above-ground structure. In order to reduce the computational cost, an efficient computational method, Three-Stage Simulation Method (TSSM), is put forward. Three different methods, Alternative Path Load Method (APLM), Direct Simulation Method (DSM) and TSSM, are used to analyze the same model which illustrates the correctness of the model and the proposed method. By comparing tilt response of the above-ground structure of different types due to progressive collapse of underground structure under its internal blast loading, it is found that the tilt response of the above-ground structure of different types is related to the foundation of the structure. For example, compared with the frame structure with basement, the frame-shear wall structure with basement can prevent structure from great tilt response. However, the tilt response of the frame-shear wall structure with raft basis is larger than that of the frame.

The embodied energy and emissions of a high-rise education building: A quantification using process-based hybrid life cycle inventory model

Due to the lack of energy intensity data for building materials and the high integration of the construction sector in national input–output tables, applications of conventional process-based life cycle inventory (LCI) and input–output (I–O) LCI models are hindered in China. This study developed a process-based hybrid LCI model to calculate the embodied energy and emissions of a typical high-rise building in China, which has a frame-shear wall and reinforced concrete frame structure. The I–O model used for building materials manufacturing is based on the 2007 Chinese economic benchmark statistics. The process-based model uses the specific data of transportation and construction activities. Results show that the embodied energy of the case building was 309,965GJ and, the energy intensity is 6.3GJm−2. The embodied energy is dominated by coal and the shares of diesel fuel and electricity in total energy were significant. The embodied emissions mainly derive from the electricity sector and gas and water production due to its intensive coal consumption. Results of the process-based hybrid model were moderately higher (5–13%) than the I–O model values.

Seismic Damage Analysis for Multi-Story Masonry Building with R. C. Frames on Ground Floor

Multi-story Masonry Building with R. C. Frames on Ground Floor (Framed-Ground Floor Structure for short) which has serious seismic damage and high collapsed rate, is the unreasonable structure system. However, the structure system not be abolished for economic reason. Collapse types of that are divided into collapse of ground floor, collapse of transition layer, global collapse. And seismic damage is also serious for frame column and shear wall. Experiences are obtained from above seismic damage, and the following aspects should be taken into account in the future. 1. The shear wall can be increased to improve stiffness of weak layer. And designer should try to arrange the walls equably. 2. In order to avoid stiffness mutation, stiffness ratio between ground frame and transition layer can be adjusted. 3. Collapse resistant design of Framed-Ground Floor Structures should be emphasized.

Test Research on Self-Tapping Screw Joints of Cold-Formed Steel Frame Shear Walls

Two different types, one is the OSB panel perpendicular to the cold-formed thin steel and another the OSB panel parallel to the cold-formed thin steel, of self-tapping screw joints of cold-formed steel frame shear walls are tested under the monotonic loading. The load-displacement curves of the test specimens are obtained and the ultimate loads Fu and the corresponding displacements δu of two different types are analyzed. Fianlly, the conclusion that the influence from the direction between OSB and cold-formed thin steel to the performance of tapping screw joints is not significant is pointed up.

A Study on the High Seismic Performance of RC Structural Walls under Reversed Cyclic Loading

In this paper, a new web reinforcement layout for RC shear walls was presented to improve the seismic performances of RC traditional walls. Two RC ductile frames and two RC framed shear wall specimens were designed and tested under cyclic loading at the National Center for Research on Earthquake Engineering. The test results showed that the proposed shear walls with extra concentric circles web reinforcement had greater ductility and higher energy dissipation than those of traditional RC shear walls. Moreover, the test results also indicated that the improved RC shear walls can effectively prevent the inclined shear cracks from happening and developing into the wall. This implies that large “X-shaped” bi-diagonal shear cracks can be avoided; instead, a number of minor cracks gradually and uniformly propagate into the wall surface. As a result, more ductile failure mode can be expected when the proposed high seismic performance of RC shear walls appear in the engineering practice.

Experimental Study of Glued Laminated Guadua Bamboo Panel as an Alternative Shear Wall Sheathing Material

Wood frame buildings have shown good performance on past earthquakes mainly because the lateral system of those buildings was able to dissipate energy without significant loss of lateral capacity. Typically, the lateral load resisting system is provided by wood shear walls, which consist of a wood frame sheathed with wood or wood-based composites, such as Plywood or OSB panels. Taking into account the increasing forest demand for wood, there is a global need to find alternative energy-efficient, renewable and eco-friendly construction materials. Giant bamboo like Guadua Angustifolia kunt emerges as an interesting construction material, since it has a fast growing rate (3 to 4 years), high strength to weight ratio and high carbon (CO2) capture capabilities. Results of a past study conducted at the Universidad de los Andes in Bogotá-Colombia reported that Glued Laminated Guadua Bamboo (GLG) has mechanical properties comparable to those of the best structural timbers in Colombia. Potential applications of GLG include not only laminated beams and columns, but also structural panels to be used as a sheathing material for wood frame shear walls. A comprehensive experimental study has been performed on GLG sheathed shear walls in order to find an alternative sheathing material for wood frame buildings as well as to explore their possible application for residential and/or commercial construction in Colombia. A series of tests were conducted on full-size shear wall specimens in order to study the influence of the wall aspect ratio and the edge nail spacing on the shear wall performance. Based on cyclic tests on shear walls, it was found that the stiffness and maximum load carrying capacity of the wall increases as edge nail spacing decreases. In contrast, the displacement ductility capacity decreases, since the rotation of the panels is restricted when the edge nail spacing is reduced. Experimental results also revealed that stiffness, maximum load capacity, and ductility of the GLG sheathed shear walls are not affected by the aspect ratio of the wall. The final stage of the present study included dynamic shake-table tests on full-size one and two-story housing units using GLG sheathed shear walls. Results showed that the units had similar performance characteristics to those of OSB and Plywood sheathed shear walls, and it was concluded that wood-GLG combination could be a viable construction alternative from a structural point of view.

Seismic performance and sensitivity of floor isolation systems in steel plate shear wall structures

Seismic floor isolation is a method for protecting nonstructural components, equipment and/or valuable building content in traditional fixed base buildings. Seismic floor isolation is achieved by isolating a secondary floor system from the primary structural floor using horizontally flexible elements called isolators. The nonstructural components, equipment and/or valuable building content is placed atop the secondary, isolated, floor system thereby decoupling the isolated component from the floor motion of the primary structural system. Though there is no codified procedure for designing floor isolation systems, the primary difference from traditional base isolation systems is the seismic input and the weight on the isolation system.In this paper results of a numerical study to investigate the performance and sensitivity of floor isolation systems (FISs) designed for the upper levels of multi-story steel plate shear wall frames are presented. The sensitivity of the performance of the FIS to variations in the steel plate shear wall’s web-plate strength and stiffness is investigated. The results of the study show FISs are able to effectively limit, on average, absolute acceleration demands on equipment in the upper levels of multi-story buildings though isolator displacement demands can be large. Further isolator displacement demands and absolute acceleration demands on the equipment are shown to be insensitive to variations in the steel plate shear wall’s material and geometric properties.

The Seismic Behavior and Failure Form in Structure of Frame-Shear Wall of High-Rise Concrete Residential Building

The high-rise concrete residential market has been a gradually urban mainstream in recent years, and frame-shear wall structure is more used for high-rise residential structures now. This kind of structure has the advantage that the combination of frame and shear wall make the space free and flexible, and therefore the whole structure has considerable rigidity. The structure can not only satisfy the needs for people living in comfortable, but also has good dynamic and static load bearing capacity. This paper analyzed the mechanics characteristics of the structure and summarized the two kinds of main failure modes of shear wall and frame structure in earthquake. On this basis, the main principles are put forward to improve the seismic behavior of the shear wall. And further some of specific measures and suggestions which can improve the seismic performance for the frame-shear structure are introduced.

Study on Rational Ratios of Lateral Stiffness for Masonry Building with Frame Structure at First Two Stories

There are two typical seismic damage characteristics to the masonry building with frame shear wall structure at first two stories, and the lateral stiffness ratio of the third storey to the second storey is one of the key factors mostly affecting the seismic performance of this kind of building. However, some factors are not considered sufficiently in current Chinese seismic codes. According to the theory of performance-based seismic design, the seismic performance of this kind of structure is analyzed in this paper by taking time-history analysis on models which with different storey stiffness ratios. The results show that when the lateral stiffness ratio controlled in a reasonable range, the upper masonry deformation can be ensured in a range of elastic roughly, and the bottom frame can be guaranteed to have sufficient deformation and energy dissipation capacity. Finally, according to the seismic performance characteristics of masonry building with frame shear wall structure at first two stories, especially the characteristics under strong earthquakes, a method of simplified calculation model for the upper masonry is discussed in this paper.

Statistical Analysis of Fundamental Periods of Frame-Shear Wall Structures

The differences of empirical formulas of China, United States, Japan, and Europe for estimating the fundamental periods of frame-shear wall structures are investigated. Summing up paradigms of the empirical formulas from the above representation countries, the paradigm formulas expressed as single-variable exponential type, single-variable linear type, and multi-variable non-linear type. Using statistical data of 88 groups of the measured fundamental period for least-squares regression analysis, and the effect of fitting regression formula is judged by the norm of relative error‖δ‖2 , the norm of root mean square error‖RMSE‖2 , and the norm of residual mass‖CRM‖2Italic textb> . The results show that: the single-variable exponential type has wide application and gets closer with measured fundamental period; the single-variable linear type is briefly, and the single-variable based on structural height has smaller error than the single-variable of stories; the multi-variable non-linear type is very complex and larger error compared with the measured fundamental period. Considering the formula in the form of simple, practical and consistent with the codes, this paper gives single-variable exponential type as recommended empirical formula for estimating the fundamental periods of frame-shear wall structures .The proposed empirical formula can serve as a reference for revision of the seismic design code, frame-shear wall structure seismic design and related studies.

Treatment Methods for Over Reinforcement of Coupling Beam in High-Rise Building Structure Design

This paper analyzes the over-reinforcement of coupling beam in high-rise building structure design and proposes the relevant treatment methods and suggestions to provide references for designers. Coupling beam is a beam that is used to connect between wall limbs or wall limbs and frame columns in shear wall structures and frame – shear wall structures. A coupling beam generally has the features of small span, large cross section and high stiffness of the wall connected to it.